Building a GUI without InterfaceBuilder in Objective-C

#import <Carbon/Carbon.h>
#import <AppKit/AppKit.h>

@interface MyApplicationDelegate: NSObject
{
    NSWindow *window;
    double e;
    long aho;
}
-(void)applicationWillFinishLaunching: (NSNotification*) aNotification;
-(void)applicationDidFinishLaunching: (NSNotification*) aNotification;
-(BOOL)applicationShouldTerminateAfterLastWindowClosed: (NSApplication *)theApplication;
@end

@implementation MyApplicationDelegate
-(void)applicationWillFinishLaunching: (NSNotification*) aNotification
{
    window = [[NSWindow alloc] initWithContentRect:
        NSMakeRect(300, 800, 500, 500)
        styleMask: (NSTitledWindowMask | NSClosableWindowMask)
        backing: NSBackingStoreBuffered
        defer: NO];
    [window setTitle: @"hoge"];
    [window makeKeyAndOrderFront: window];
    [window makeMainWindow];

    NSButton *btn = [[NSButton alloc] initWithFrame: NSMakeRect(10, 10, 120, 24)];
    // [btn setBezelStyle: NSRoundedBezelStyle];
    [btn setBezelStyle: NSRegularSquareBezelStyle];
    [[window contentView] addSubview: btn];
    [btn release];
}

-(void)applicationDidFinishLaunching: (NSNotification*) aNotification
{
}

-(BOOL)applicationShouldTerminateAfterLastWindowClosed: (NSApplication *)theApplication
{
    return YES;
}

-(void)dealloc
{
    [window release];
    [super dealloc];
}
@end

int main(int argc, char **argv)
{
    static const ProcessSerialNumber thePSN = { 0, kCurrentProcess };
    TransformProcessType(&thePSN, kProcessTransformToForegroundApplication);
    SetFrontProcess(&thePSN);
    NSAutoreleasePool *aPool = [[NSAutoreleasePool alloc] init];
    [NSApplication sharedApplication];
    MyApplicationDelegate *aMyApplicationDelegate = [[MyApplicationDelegate alloc] init];
    [NSApp setDelegate: aMyApplicationDelegate]; 
    [aPool release];
    [NSApp run];
    return 0;
}